I think if you limit it to close connections there won’t be any liquidity. Will be very hard to ever find someone on the other end to fulfill your order. Perhaps you find one or two friends willing to do it but my guess would be it doesn’t scale well.

There are definitely services that do this but they are full of fraud. Most of the sellers willing to take a 10%+ haircut on their Amazon to BTC conversions were using stolen money (phone tech support gift card scams etc). 

 My experience was different in Madeira, I have several friends that constantly wanted to pay by card for my sats

Fraud would be extremely rare if connecting with close people